A. Field of the Invention
The invention generally concerns the use of a support material for hydrocarbon gas reforming catalysts. In particular, the support material includes an alkaline earth metal/metal oxide compound or a mixture of such compounds.
B. Description of Related Art
Synthesis gas or “syngas” is a gas mixture that includes carbon monoxide and hydrogen. Syngas is typically used as an intermediary gas to produce a wide range of various products, such as mixed alcohols, hydrogen, ammonia, i-C4 hydrocarbons, mixed alcohols, Fischer-Tropsch products (e.g., waxes, diesel fuels, olefins, gasoline, etc.) methanol, ethanol, aldehydes, alcohols, etc. Syngas can also be used as a direct fuel source, such as for internal combustible engines.
One of the more common methods of producing syngas is by oxidizing hydrocarbon gases such as methane. For instance, the controlled oxidation of methane can be carried out using carbon dioxide, water, or oxygen or a combination of such materials. For industrial scale applications, methane can be reformed into syngas by using steam, such as by the following reaction:CH4+H2O→CO+3H2 The ratio of CO/H2 obtained by using this process is approximately 1:3 or 0.33. One of the issues with this ratio is that applications for producing aldehydes, alcohols, and ammonia require a ratio of CO/H2 of about 1:1 or 1. Therefore, the current solution is to remove excess H2 from the produced syngas via separation techniques which can decrease efficient production while simultaneously increasing associated costs. A 1:1 ratio can also be obtained by replacing water with carbon dioxide or a mixture of carbon dioxide and oxygen, such as by the following reactions:CH4+CO2→2CO+2H2 2CH4+CO2+O2→3CO+3H2+H2O.
Catalysts are used to drive the above reforming reactions. One of the issues with current catalysts is that they are prone to sintering, which can reduce the active surface area of the catalytic material, thereby reducing the efficiency of the catalyst. Another issue is that of carbon formation or coking, which can also occur on the catalytic material. The catalysts used in the above methane/carbon dioxide reforming reactions are especially prone to sintering and coking issues, both on the surface of the actual catalytic material and the surface of the support material.